Apparatus and method for managing power for mobile device

ABSTRACT

An apparatus and method of managing power for a mobile device is disclosed, which can prevent an inflow of overcurrent to the device when the device is charged. The apparatus includes a state judgment unit to judge whether a battery of the mobile device is being charged, a voltage level detection unit to detect a voltage level of the battery if the battery is judged as being charged, and a control unit to control a driving of the mobile device in accordance with the detected voltage level.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No.13/751,404, filed Jan. 28, 2013, which is a continuation of Ser. No.11/505,900, filed Aug. 18, 2006, which claims the benefit of KoreanPatent Application No. 2005-83325, filed Sep. 7, 2005, in the KoreanIntellectual Property Office, the disclosures of which are incorporatedherein in their entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Aspects of the present invention relate to an apparatus and method ofmanaging power for a mobile device, and, more particularly, to anapparatus and method of managing power for a mobile device that preventsan inflow of overcurrent to the device when the device is charged.

2. Description of the Related Art

Generally, mobile devices, such as mobile phones and personal digitalassistants (PDAs) have both a detachable and a rechargeable battery.These batteries are charged using an adapter when the batteries aremounted in the mobile device or when the batteries are separated fromthe mobile device.

Since a user of a mobile device should always carry an adapter if he/sheintends to charge the mobile device while he/she is moving, a method ofcharging a battery of a mobile device using a universal serial bus(USB), which is a peripheral device connection standard of a computer,has recently been used. According to this method, a USB port provided onthe mobile device is connected to a USB port of a personal computer(PC), such as a desktop or a notebook computer, through a specifiedinterface cable, and the battery of the mobile device is charged withpower being supplied through the USB port.

FIG. 1 is a schematic view illustrating a mobile device having a batterywhich is charged using a general adapter. As shown in FIG. 1, an adapter20, connected to a specified commercial power supply, is connected to amobile device 10 through a specified interface cable 21. In this case,the adapter 20 converts a commercial power supply (e.g., an AC powersupply) into a DC power supply having a specified voltage level, andsupplies the converted DC power supply to the mobile device 10.Accordingly, a battery of the mobile device 10 is charged with the DCpower supply being supplied through the adapter 20.

FIG. 2 is a schematic view illustrating a mobile device of which thebattery is charged using a general PC. As shown in FIG. 2, where a portprovided on a mobile device 10 is connected to a port provided on a PC30 through a specified interface cable 31, either the mobile device 10transmits/receives data to/from the PC, or a battery of the mobiledevice 10 is charged through the interface cable 31. This method ofcharging a battery of a mobile device through a PC is frequently used byoffice workers since most office workers use PCs for their business.

However, where a battery of a mobile device is charged using the portprovided on the PC 30, a power level that is supplied through the portis generally fixed, while an adapter to charge a battery of a mobiledevice is manufactured according to the standard of a power level (e.g.,voltage and current) suitable for a specified mobile device. Forexample, the voltage/current that can be supplied through a USB port ofthe PC 30 is generally set to 5V/500 mA.

On the other hand, if the mobile device is in a low-battery state, i.e.,if the power required to drive the mobile device 10 is insufficient, themobile device 10 maintains a minimum power level to protect the system.Generally, when the mobile device 10 maintains the minimum power state,the mobile device 10 is maintained in a power-off state.

Generally, no abnormal phenomenon occurs when charging the battery ofthe mobile device 10 through the port provided on the PC 30 where thepower of the mobile device 10 is turned off due to the low-battery stateof the mobile device 10. However, when a user turns on the power justafter the battery is charged, the mobile device 10 instantaneouslysecures current required to drive the system of the mobile device 10.This may result in overcurrent flowing into the mobile device 10. If theovercurrent flows into the mobile device 10, the voltage level requiredto drive the system of the mobile device 10 is relatively lowered tocause the necessary voltage level to not be secured.

Accordingly, as soon as the user turns on the power of the mobile device10, the mobile device 10 may be switched to the minimum power state, oran abnormality may occur in the system of the mobile device 10.

Korean Patent Unexamined Publication No. 2004-9662 discloses anapparatus and a method of automatically turning on the power of a mobilecommunication terminal when the charging of a battery of the mobileterminal is completed where the power of the mobile terminal is turnedoff. However, this publication does not disclose a scheme of preventingan inflow of overcurrent to the mobile terminal when the power of themobile terminal is turned on simultaneously with the start of chargingthe battery in a state that the mobile terminal is in a low-batterystate.

SUMMARY OF THE INVENTION

Accordingly, aspects of the present invention solve the above-mentionedand/or other problems occurring in the related art, and to provide anapparatus and a method of managing power for a mobile device capable ofpreventing an abnormal phenomenon which may occur in a system of themobile device by preventing an inflow of overcurrent to the mobiledevice that may occur when the power of the mobile device is turned onjust after the start of charging the battery.

In order to accomplish these and/or other aspects, there is provided anapparatus to manage power for a mobile device, which includes a statejudgment unit to judge whether a battery of the mobile device is beingcharged, a voltage level detection unit to detect a voltage level of thebattery if the battery is being charged as a result of the judgment, anda control unit to control whether to drive the device in accordance withthe detected voltage level.

In another aspect of the present invention, there is provided a methodof managing power for a mobile device, comprising judging whether abattery of the mobile device is being charged, detecting a voltage levelof the battery if the battery is judged as being charged, andcontrolling a driving of the mobile device in accordance with thedetected voltage level.

Additional and/or other aspects and advantages of the invention will beset forth in part in the description which follows and, in part, will beobvious from the description, or may be learned by practice of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofthe embodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a schematic view illustrating a mobile device the battery ofwhich is charged using a general adapter;

FIG. 2 is a schematic view illustrating a mobile device of which thebattery is charged using a general PC;

FIG. 3 is a block diagram illustrating the construction of an apparatusto manage power for a mobile device according to an embodiment of thepresent invention; and

FIG. 4 is a flowchart illustrating a method of managing power for amobile device according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The embodiments are described below in order to explain thepresent invention by referring to the figures.

It will be understood that each block of the flowchart illustrations,and combinations of blocks in the flowchart illustrations, may beimplemented by computer program instructions. These computer programinstructions may be provided to a processor of a general purposecomputer, special purpose computer, or other programmable dataprocessing apparatus to produce a machine, such that the instructions,which execute via the processor of the computer or other programmabledata processing apparatus, allow for the implementing of the functionsspecified in the flowchart block or blocks.

These computer program instructions may also be stored in a computerusable or computer-readable memory that directs a computer or otherprogrammable data processing apparatus to function in a particularmanner, such that the instructions stored in the computer usable orcomputer-readable memory produce an article of manufacture includinginstructions that implement the function specified in the flowchartblock or blocks.

The computer program instructions may also be loaded onto a computer orother programmable data processing apparatus to cause a series ofoperations to be performed on the computer or other programmableapparatus to produce a computer implemented process such that theinstructions that execute on the computer or other programmableapparatus provide operations to implement the functions specified in theflowchart block or blocks.

Also, each block of the flowchart illustrations may represent a module,segment, or portion of code, which comprises one or more executableinstructions to implement the specified logical function(s). It shouldalso be noted that in some alternative implementations, the functionsnoted in the blocks may occur out of the order. For example, two blocksshown in succession may in fact be executed substantially concurrentlyor the blocks may sometimes be executed in the reverse order, dependingupon the functionality involved.

FIG. 3 is a block diagram illustrating the construction of an apparatusto manage power for a mobile device according to an embodiment of thepresent invention. As shown in FIG. 3, the apparatus includes a battery110, a state judgment unit 120 to judge the charging state of thebattery, a power level limitation unit 130 to limit the level of powerthat is used for a battery charging, a voltage level detection unit 140to detect a voltage level of the battery 110, and a control unit 150 tocontrol whether to drive the mobile device in accordance with thedetected voltage level.

The state judgment unit 120 judges whether the battery 110 is chargedthrough a dedicated adapter or through a USB port of a PC, and judgeswhether the battery is being charged. In other words, the state judgmentunit judges the type of an interface to charge the battery 110. In thiscase, the state judgment unit 120 judges the type of the connectedinterface (i.e., whether the mobile device is connected through anadapter or a USB port, through a type of an interface cable connected tothe mobile device or the type of a signal being transmitted/received).

In the embodiment of the present invention, the battery 110 is chargedusing a USB port of a PC in addition to the dedicated adapter. However,the present invention is not limited to this arrangement, and diverseinterfaces such as those described in the IEEE 1394 standard may also beused to provide the power supply.

In addition, the state judgment unit 120 controls a switching unit 121that switches paths through which the power is transferred in accordancewith the type of an interface connected to the mobile device. Accordingto an embodiment of the present invention, the switching unit 121comprises switching elements (e.g., transistors) that switch circuitpaths to transfer the power being supplied under the control of thestate judgment unit 120. That is, the power being supplied may bedirectly transferred to the battery of the mobile device or to thebattery through a power management device of the mobile device, inaccordance with an interface connected to the mobile device such as anadapter or a USB port.

Where the power being is transferred to the battery through the powermanagement device of the mobile device (i.e., the adapter), which maysupply a sufficient power to the battery to match the standard of thecorresponding mobile device, as the interface, the power is directlysupplied to the mobile device without passing through a separateprocess, while in the case of using the USB port, through which alimited power is supplied, the power is supplied to the mobile devicethrough a corresponding path that is selected according to the type ofan interface used for the supplying of the power.

The power level limitation unit 130 limits the level of the power usedto charge the battery 110 when the battery 110 is charged through aspecified interface (e.g., an adapter or a USB port). According to anembodiment of the present invention, the power level limitation unit 130limits the power level used to charge the battery 110 to 5V/500 mA, andthe power level that is limited by the power level limitation unit 130may be changed according to the standard of the mobile device.

The voltage level detection unit 140 detects the voltage level of thebattery 110 when the battery is charged. If the detected voltage levelof the battery 110 reaches a predetermined reference power level, thevoltage level detection unit 140 outputs a specified signal. Asdescribed above, if the power of the mobile device is turned on justafter the start of charging the battery 110, an overcurrent flows to themobile device, which requires a large current to drive the system, and,thus, a relatively low voltage level, to cause an abnormal phenomenon tooccur in the system of the mobile device. The term “reference powerlevel” refers to a power level which prevents the abnormal phenomenonfrom occurring in the system of the mobile terminal as described above.In an embodiment of the present invention, it is exemplified that thereference power level is set to 3.7V, although, it is understood thatthere are other voltages that could be employed to prevent the abnormalphenomenon of an overcurrent flow from occurring.

The control unit 150 outputs a control signal to determine whether todrive the mobile device in accordance with the output signal of thevoltage level detection unit 140. In other words, if the specifiedsignal is outputted from the voltage level detection unit 140, thecontrol unit 150 judges that the battery 110 has been charged with thepower over the reference power level. Otherwise, the control unit 150judges that the battery 110 has not been charged with the power over thereference power level.

If it is judged that the battery 110 has been charged with the powerover the reference power level, the control unit 150 judges thatsufficient voltage level to drive the system of the mobile device hasbeen secured even if the power of the mobile device is turned on, and,thus, controls the power of the mobile device to be turned on. Bycontrast, if it is judged that the power being charged does not reachthe reference power level, the control unit 150 judges that the voltagelevel may be reduced due to an inflow of overcurrent if the power of themobile device is turned on, and controls the power of the mobile deviceto not be turned on.

Specifically, the control unit 150 controls a drive signal output unit151 to output a drive signal to activate a power button provided on themobile device if it is judged that the battery has been charged with thepower over the reference power level. Otherwise, the control unitcontrols the drive signal output unit 151 to not output the drivesignal.

Accordingly, in the event that the voltage level of the battery 110 doesnot reach the reference voltage level, the power is not turned on evenif a user presses the power button. Thus, an inflow of overcurrent tothe mobile device is prevented, in advance.

Hereinafter, a method of managing power for a mobile device according toan embodiment of the present invention will be explained in detail.

FIG. 4 is a flowchart illustrating a method of managing power for amobile device according to an embodiment of the present invention.

According to the method, it is understood that a battery 110 of themobile device is charged with the battery 110 being in a minimum powermode, i.e., the power of the mobile device is turned off. Also,according to the method, it is understood that the battery 110 of themobile device is charged through a USB port or an IEEE 1394 compatibleport that is provided on a PC such as a desktop computer or a notebookcomputer.

As is illustrated in FIG. 4, the mobile device is first connected to adevice that provides power to charge the battery 110 of the mobiledevice through a specified interface cable when the battery 110 ischarged (operation 110).

If the interface cable is connected to the mobile device, the statejudgment unit 120 judges that the mobile device is in a charging state(operation 120).

In addition, the state judgment unit 120 judges whether the battery 110of the mobile device is charged through an adapter by checking theconnected interface cable (operation 130). In other words, the statejudgment unit judges whether the battery 110 of the mobile device ischarged through an adapter or a USB port of a PC in accordance with thetype of the interface cable connected to the mobile device. As describedabove, where the mobile device is charged through the adapter, which maysupply a sufficient power to the mobile device, turning on the power ofthe mobile device just after the start of charging does not present aproblem, while where the mobile device is charged through the USB portof the PC, an inflow of overcurrent may occur when the power of themobile device is turned on just after the start of charging.

If it is judged that the battery 110 is charged though the USB port ofthe PC, the voltage level detection unit 140 detects the voltage levelof the battery 110 being charged (operation 140). At this time, thelevel of power being supplied when the battery 110 is charged may belimited to a specified power level.

Here, the voltage level detection unit 140 compares the detected voltagelevel of the battery 110 with a reference voltage level (operation 150).If the detected voltage level exceeds the reference voltage level, thevoltage level detection unit 140 outputs a specified signal to thecontrol unit 150.

When the specified signal is received from the voltage level detectionunit 140, the control unit 150 judges that a voltage level that issufficient to drive the system of the mobile device has been securedeven if the power of the mobile device is turned on, and, thus, allowsthe mobile device to be turned on (operation 160). For example, when auser turns on the power of the mobile device through a power buttonprovided on the mobile device, the control unit 150 controls the drivesignal output unit 151 to output the drive signal to activate the powerbutton. By contrast, if the specified signal is not received, thecontrol unit 150 judges that the voltage level may be reduced due to aninflow of overcurrent, and controls the drive signal output unit 151 notto output the drive signal, and, thus, not allow the mobile device to beturned on.

On the other hand, in the case in which the mobile device is chargedthrough the adapter in operation 130, the adapter supplies a sufficientpower to the mobile device, and, thus, the mobile device may be directlyturned on without performing the above-described operations 140 to 160.

According to the embodiments of the present invention, the term “unit”,as used herein, means, but is not limited to, a software or hardwarecomponent, such as a Field Programmable Gate Array (FPGA) or anApplication Specific Integrated Circuit (ASIC), which performs certaintasks. A module may advantageously be configured to reside on theaddressable storage medium and configured to execute on one or moreprocessors. Thus, a module may include, by way of example, components,such as software components, object-oriented software components, classcomponents and task components, processes, functions, attributes,procedures, subroutines, segments of program code, drivers, firmware,microcode, circuitry, data, databases, data structures, tables, arrays,and variables. The functionality provided for in the components andmodules may be combined into fewer components and modules or furtherseparated into additional components and modules.

As is described above, according to aspects of the apparatus and themethod to manage power for a mobile device according to the presentinvention, the drop of the voltage level to drive the mobile device,which occurs due to an inflow of overcurrent to the mobile device whenthe power of the mobile device is turned on just after the start ofcharging the battery, may be prevented, and, thus, the occurrence of anabnormal phenomenon in the system of the mobile device, which includes apower turn-off, may also be prevented.

Although a few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in these embodiments without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

1. A mobile device comprising: a battery; a voltage level detection unitto detect a voltage level of the battery while the battery is beingcharged with an external power source; and a control unit to prevent themobile device from being turned on if the voltage level detected by thevoltage level detection unit is lower than a predetermined referencevoltage level and the battery is being charged via a universal serialbus (USB) interface.
 2. The device of claim 1, wherein the voltage leveldetection unit transmits a signal to the control unit if the detectedvoltage level exceeds the predetermined reference voltage level.
 3. Thedevice of claim 2, wherein the control unit controls a driving of themobile device in accordance with an existence/nonexistence of thesignal.
 4. The device of claim 1, further comprising: a power levellimitation unit to limit a power level supplied to the battery when thebattery is being charged; and a drive signal output unit to output adrive signal to drive the mobile device under control of the controlunit.
 5. The device of claim 1, further comprising: a state judgmentunit to sense whether a specified interface cable is connected to a portprovided for the charging of the battery of the mobile device, and tojudge whether the battery is being charged in accordance with the resultof the sensing.
 6. A method of managing power for a mobile device, themethod comprising: detecting a voltage level of a battery of the mobiledevice while the battery is being charged with an external power source;and preventing the mobile device from being turned on if the detectedvoltage level is lower than a predetermined reference voltage level andthe battery is being charged via a universal serial bus (USB) interface.7. The method of claim 6, wherein the detecting the voltage levelcomprises outputting a signal if the detected voltage level exceeds thepredetermined reference voltage level.
 8. The method of claim 7, furthercomprising controlling a driving of the mobile device in accordance withan existence/nonexistence of the signal.
 9. The method of claim 6,further comprising: limiting a power level supplied to the battery whenthe battery is being charged; and outputting a drive signal to drive themobile device.
 10. The method of claim 6, further comprising: sensingwhether a specified interface cable is connected to a port provided forthe charging of the battery of the mobile device; and judging whetherthe battery is being charged in accordance with the result of thesensing.